1. Technical Field
The present invention relates to an apparatus and process for detecting an abnormality in a recorded signal, and, more particularly, to apparatus and processes for detecting abnormalities in recorded signals during the recording of the signal onto a recording medium.
2. Related Art
Generally, a digital magnetic recorder/player such as a digital video cassette (DVC), or the like, records and reproduces a digital signal, with advantages of higher quality of image and sound over an analog type signal, and also an easier editing process. The digital magnetic recorder/player generally uses a magnetic tape as a recording medium for storing the digital data of image and sound. Heads are formed on a rotary head drum of the recorder/player to record and reproduce signals on and from the magnetic tape.
During the use of the recorder/player, possibility is high that foreign substances are transferred from the magnetic tape to the head. Another high possibility is that foreign substances, floating in air, can be attached to the surface of the head. In the event that foreign substances are attached to the surface of the head, malfunction occurs in recording or reproducing process, causing undesired and abnormal signal recording or reproducing. In order to eliminate the foreign substances, a foreign substance cleaning tape is used, and sometimes, a user eliminates the foreign substances manually.
The source of abnormal recording/reproducing comes not only from the presence of foreign substances on the surface of the head, but also from problems associated with the head itself, or the errors of peripheral circuits which supply recorded signal to the head. Whether the abnormal signal recording is caused by the presence of foreign substances on the head or from problems associated with the head or other devices, the overriding difficulty is that the user does not immediately learn about the presence of the abnormality because the user is not provided with any way to either detect the occurrence of the abnormality or to identify or otherwise locate the cause of the abnormality. Although a user could consider the quality of image and sound for determining abnormal signal recording through the user's anatomical audio and visual senses during reproducing process, during the recording process, the user is not able to determine if the abnormal signal is being recorded or if the information that is being recording is not being recorded at all. As a result, the user usually keeps recording for a long period of time, only to find that all of the user's labors were a waste of time and effort. I have noticed that recording operations that produce errors or abnormalities can be extremely inconvenient; often the recording efforts can not be recreated once the defective equipment has been repaired or replaced. Efforts have been made to improve recording technologies.
Exemplars of recent efforts in the art include U.S. Pat. No. 6,141,486 for METHODS AND APPARATUS FOR RECORDING DIGITAL DATA INCLUDING SYNC BLOCK AND TRACK NUMBER INFORMATION FOR USE DURING TRICK PLAY OPERATION issued to Lane et al., U.S. Pat. No. 4,849,979 for FAULT TOLERANT COMPUTER ARCHITECTURE issued to Maccianti et al, U.S. Pat. No. 6,141,164 for DATA RECORDING/REPRODUCING APPARATUS EMPLOYING READ-AFTER-WRITE SYSTEM issued to Ishibashi et al., U.S. Pat. No. 6,134,384 for DIGITAL SIGNAL RECORDING/REPRODUCING APPARATUS AND RECORDING METHOD issued to Okamoto et al., U.S. Pat. No. 5,291,342 for MULTIFUNCTIONAL CONTROL TYPE VIDEO HEAD SELECTING DEVICE AND METHOD THEREOF issued to Kim, and U.S. Pat. No. 6,163,421 for AZIMUTH MAGNETIC RECORDING AND REPRODUCING APPARATUS AND METHOD EMPLOYING WAVEFORM EQUALIZATION issued to Shinpuku et al. While these recent efforts provide advantages, I note that they fail to adequately provide an apparatus and method for efficiently and conveniently detecting abnormalities in recorded signals.